You will need to provide some system files from Windows 7 SP0 (x86) for most applications to work. However, here is Win7 booted using just 69MB of space (70 after the first reboot). You're also able to squeeze a few more MB by going through the registry but I really can't be bothered for that fine detail.
To boot
1: Press enter when bootmgr complains that it could not verify the kernel
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9/11
